Bitcoin Forum

On order tomorrow, if that works out... a new farm is born.

Anyhow.

I try to get 3 x 6990 into one rig, and I have problems theoretically with the power supply side.

The idea is to go high density, energy efficient.

The 6990 needs 2x8 pins. It also uses 450 watts under full OC load.

1200 watt supplies should not be enough, right? Even not overclocked, 375 watts x 3 would overload the level such a power supply could safely handle? This would mean a 1500 watt supply for 3, without OC ability? ;?

Even then, how do I handle the power input? The http://www.alternate.de/html/product/SilverStone/ST1500/151271/? has only 4x6+2 and 4x6.... while the cards would need a total of 6x6+2.

Anyone a recommendation?

Due to side costs involved for a larger setup (like the cost of space) I plan of going with a dense setup.

i dont know if i am correct or not
from what i understand, is that unless you have the right configuration, your going to need more power

you can lower power first by putting in 1 card, make sure to cpu core is default or lower by 20 to 30 points with msi afterburner, while underclocking the hell out of the memory down to 300 , 400 maybe even 500

, install second card, do the same, then do the third, find the memory clock sweetspot, then start going default cpu clock speed, then over clocking from there

thats assuming your video cards are not so close together, and they just overheat each other by being so close, unless you got a type of high airflow case with a couple of fans

i think you need Video cards that pull Air from the Sides or at the Ends,

besides if your spending alot of money, you might as well buy a  1300 to 1500 powersupply, it shouldn't be but dam 20 to 50 to 100 bux for more power,

Yeah and don't forget to put this rig on it's own dedicated 15A circuit. In other words don't try to plug this mining rig on the circuit you have your toaster on or something of that sort.

Well, it is not that much power - or: being in europe it is not 15A ;) We use 230 volts here.

How about the cabling? I am concernved about not having enough 6+2 connectors.

230V 13A i believe so it's actually less than the 15A their talking about. I'm not sure though

Right, well, I did not know you were in Europe. I though that the most common circuits in Europe are 16 amps. But either way cause of the higher voltage you can - non technically speaking - squeeze more electrons though and get a higher work load out of it - 3680 watts from an European 16 amp circuit.

But all that aside I'd say that if you get a decent high end power supply (which you'd have to in order to power 3 6990s) it will come with plenty of 6+2 connectors.  Typically some power supplies have two 6+2 connectors on the main wire bundle coming out of the power supply and they'd also have 4 additional 6+2 connectors that would be modular.

Sorry. I just check since I wasn't sure. apparently it'd be 2.5A 230V if it's the one described in Type C. under http://en.wikipedia.org/wiki/AC_power_plugs_and_sockets#Type_C

if any one knows how to check the current drew on your rig please let me know. I'd like to reconfigure my home's sockets to accommodate more rigs.

Looking at the price curve of 1000W+ PSU's, I'd say you'd be better off just building rigs with 2x6990, or rigs with 3-4 5850's. The price gets astronomical when you get into the 1350W+ PSU's.

I'd have to agree. Even though you can power 3 6990s with a 1200 Watt unit you'd still be pushing it. It's good to leave a fair bit of head room with high efficiency PSUs. Often they operate at peak efficiency at ~80% or below load. You never want to get close to the peak load it can support because not only will you shorten its lifespan but because it will also pump out more heat due to inefficiency heat losses.

Atroxes, I like your signature..so I take it you've got yourself a incognito mining rig in a garbage can with a power line running to a nearby power pole? ;)

Also please be aware that dual GPU cards draw sometimes more electricity than what's in the spec over their PCIe connectors!

With multiple ones, this might leads to quite a few problems/accidents. I hope you have a smoke alert in your mining room!

Or be there with a bag of marshmallows when shit really hits the fan (metaphorically speaking)..

My dual 6990 rig with GPUs oc'd to 940 core clock and underclocked memory 625 runs at 11 amps with a 1500 watt power supply running 24/7 7 days a week. It blows air with the power of 10 blow-driers on their hottest setting as well. I could literally setup a clothesline behind it and dry my wash.

I recommend getting a kill-a-watt (http://amzn.to/jBt0rJ) and do some testing to make sure you don't burn down your place lol

Indeed! Getting some sort of energy meter is a must!

Seriously?

Becasue basically one company in germany starts selling his rig for a competitive price (as in: I consider just ordering it from them).

http://www.miningrigs.com/

Note - I am not associated with them. Looks like they went to the same site I did, and their price is such that I consider just buying, a lot less work than putting together.

He goes with 1250 watt....  bood idea.

This would indicate feasibility - selling a compponent like this means the shop is responsible for the stability of the setup ;)

I dunno about you guys but putting together the mining rigs is half the fun for me :) The other half is watching them make BTC 4 me.

Maybe his signature is in some way linked to his avatar ;)

Now way! Could it be! lol

To be honest I did not even pay attention to his avatar when I made that post.